What it is and what the key ratings mean
The Siemens 3VA2116-5HN36-0HA0 is a 3-pole IEC molded-case circuit breaker on a 160 A frame, fitted with an ETU350 electronic trip unit providing LSI protection (long-time, short-time, instantaneous). Its headline rating is a breaking capacity Icu of 55 kA at 415 V AC — that means it can safely interrupt a fault current up to 55,000 A without welding contacts or rupturing the case, which is the class M rating for the 3VA2 platform. For a 160 A frame, 55 kA gives solid headroom for most industrial distribution panels where the prospective fault current at the main breaker is in the 25–50 kA range. The ETU350 offers adjustable overload protection Ir from 63 A to 160 A, short-time pickup Isd from 1.5 to 10 × Ir, and a fixed instantaneous pickup Ii at 10 × In. That LSI curve set lets you coordinate downstream breakers and still clear a hard fault fast — typical for feeder duty to motor control centers or sub-distribution boards.
Trip unit and auxiliary functions
This variant includes a shunt trip (STL) rated for 12–30 V DC and 24 V AC at 50/60 Hz. The shunt trip is what lets a remote signal — from an emergency-stop relay, a fire-alarm panel, or a PLC-driven safety contact — open the breaker without an operator at the handle. The 12–30 V DC range covers standard 24 V DC control supplies with margin. Connections are clamp-type (box lug), which accept a range of conductor sizes without needing compression lugs — common in panel building where termination speed and rework flexibility matter.
Where it fits in the panel
The 3VA2 frame mounts on a DIN rail or can be screw-fixed to a backplate. At 160 A frame size, it occupies three pole widths (roughly 105 mm) and needs clearance for the operating handle and arc-chute venting — standard for IEC molded-case breakers in distribution boards.